Nitrogen-Periodic Diamond Single Crystal for Wear-Resistant Tools
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Synthetic diamond single crystals used in tools often have low mechanical properties due to nitrogen impurities, leading to reduced tool life and uneven wear.
Innovation Solution
A diamond single crystal is produced using a temperature difference method with a solvent metal containing nitride exceeding 0% to less than 3% by mass, where the nitrogen concentration is optimized between 10 ppm and 1000 ppm, and the temperature change in the low-temperature part of the solvent metal is less than 1% of the predetermined temperature, resulting in improved wear resistance and defect resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If nitrogen impurity concentration is increased in synthetic diamond single crystal, then the diamond can be more easily synthesized, but the mechanical properties deteriorate and tool life becomes low
Solution Approach 1:
The patent applies parameter changes by precisely controlling the nitrogen concentration in the solvent metal within the range of 0.01-3 mass%, and controlling the temperature change rate in the low-temperature part to be less than 1% of the predetermined temperature. This optimization of parameters allows nitrogen to be incorporated in a controlled manner that improves synthesis ease while maintaining mechanical properties through the formation of a specific periodic structure.
2Ease of manufacture
If nitrogen impurity concentration is increased in synthetic diamond single crystal, then the diamond can be more easily synthesized, but wear resistance becomes low due to uneven wear
Solution Approach 1:
The patent applies local quality by creating a periodic structure within the diamond single crystal through controlled nitrogen incorporation. This periodic structure is formed by maintaining specific temperature conditions during synthesis, resulting in localized variations in nitrogen concentration that create alternating regions of different properties, thereby improving wear resistance while maintaining ease of synthesis.
3Quantity of substance
If natural diamond single crystal is used, then high purity can be achieved (type IIa), but many internal distortion and defects are present making it unsuitable for tool applications
Solution Approach 1:
The patent applies the principle of converting harm into benefit by deliberately incorporating nitrogen impurities into the diamond single crystal through controlled synthesis conditions. Instead of avoiding nitrogen as in type IIa diamonds, the patent uses nitrogen at controlled concentrations (0.01-3 mass% in solvent metal) to create a periodic structure that actually improves the crystal's suitability for tool applications, transforming the typically harmful impurity into a beneficial structural feature.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method enhances the mechanical properties of diamond single crystals, leading to improved tool life and wear resistance, making them suitable for wear-resistant and cutting tools without impairing thermal and mechanical properties.
Implementation Method 1
growing a diamond single crystal on a diamond seed crystal by a temperature difference method using a solvent metal
Implementation Method 2
using a solvent metal where the content of nitride in the solvent metal during synthesis of the diamond single crystal is exceeding 0% by mass and less than 3% by mass
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
The present diamond single crystal is a diamond single crystal containing nitrogen atoms, in which a concentration of the nitrogen atoms changes periodically along a crystal orientation of the diamond single crystal, and an arithmetic average value Aave, a maximum value Amax, and a minimum value Amin of the distance of one period along the crystal orientation satisfy the relationship expressed by the following equation (I): Amax/1.25≤Aave≤Amin/0.75